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Merge branch 'for-3.5' of ../cgroup into block/for-3.5/core-merged
[linux-2.6-block.git] / drivers / mtd / nand / docg4.c
CommitLineData
570469f3
MD		 1/*
2 * Copyright © 2012 Mike Dunn <mikedunn@newsguy.com>
3 *
4 * mtd nand driver for M-Systems DiskOnChip G4
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * Tested on the Palm Treo 680. The G4 is also present on Toshiba Portege, Asus
12 * P526, some HTC smartphones (Wizard, Prophet, ...), O2 XDA Zinc, maybe others.
13 * Should work on these as well. Let me know!
14 *
15 * TODO:
16 *
17 * Mechanism for management of password-protected areas
18 *
19 * Hamming ecc when reading oob only
20 *
21 * According to the M-Sys documentation, this device is also available in a
22 * "dual-die" configuration having a 256MB capacity, but no mechanism for
23 * detecting this variant is documented. Currently this driver assumes 128MB
24 * capacity.
25 *
26 * Support for multiple cascaded devices ("floors"). Not sure which gadgets
27 * contain multiple G4s in a cascaded configuration, if any.
28 *
29 */
30
31#include <linux/kernel.h>
32#include <linux/slab.h>
33#include <linux/init.h>
34#include <linux/string.h>
35#include <linux/sched.h>
36#include <linux/delay.h>
37#include <linux/module.h>
38#include <linux/export.h>
39#include <linux/platform_device.h>
40#include <linux/io.h>
41#include <linux/bitops.h>
42#include <linux/mtd/partitions.h>
43#include <linux/mtd/mtd.h>
44#include <linux/mtd/nand.h>
45#include <linux/bch.h>
46#include <linux/bitrev.h>
47
48/*
49 * You'll want to ignore badblocks if you're reading a partition that contains
50 * data written by the TrueFFS library (i.e., by PalmOS, Windows, etc), since
51 * it does not use mtd nand's method for marking bad blocks (using oob area).
52 * This will also skip the check of the "page written" flag.
53 */
54static bool ignore_badblocks;
55module_param(ignore_badblocks, bool, 0);
56MODULE_PARM_DESC(ignore_badblocks, "no badblock checking performed");
57
58struct docg4_priv {
59 struct mtd_info *mtd;
60 struct device *dev;
61 void __iomem *virtadr;
62 int status;
63 struct {
64 unsigned int command;
65 int column;
66 int page;
67 } last_command;
68 uint8_t oob_buf[16];
69 uint8_t ecc_buf[7];
70 int oob_page;
71 struct bch_control *bch;
72};
73
74/*
75 * Defines prefixed with DOCG4 are unique to the diskonchip G4. All others are
76 * shared with other diskonchip devices (P3, G3 at least).
77 *
78 * Functions with names prefixed with docg4_ are mtd / nand interface functions
79 * (though they may also be called internally). All others are internal.
80 */
81
82#define DOC_IOSPACE_DATA 0x0800
83
84/* register offsets */
85#define DOC_CHIPID 0x1000
86#define DOC_DEVICESELECT 0x100a
87#define DOC_ASICMODE 0x100c
88#define DOC_DATAEND 0x101e
89#define DOC_NOP 0x103e
90
91#define DOC_FLASHSEQUENCE 0x1032
92#define DOC_FLASHCOMMAND 0x1034
93#define DOC_FLASHADDRESS 0x1036
94#define DOC_FLASHCONTROL 0x1038
95#define DOC_ECCCONF0 0x1040
96#define DOC_ECCCONF1 0x1042
97#define DOC_HAMMINGPARITY 0x1046
98#define DOC_BCH_SYNDROM(idx) (0x1048 + idx)
99
100#define DOC_ASICMODECONFIRM 0x1072
101#define DOC_CHIPID_INV 0x1074
102#define DOC_POWERMODE 0x107c
103
104#define DOCG4_MYSTERY_REG 0x1050
105
106/* apparently used only to write oob bytes 6 and 7 */
107#define DOCG4_OOB_6_7 0x1052
108
109/* DOC_FLASHSEQUENCE register commands */
110#define DOC_SEQ_RESET 0x00
111#define DOCG4_SEQ_PAGE_READ 0x03
112#define DOCG4_SEQ_FLUSH 0x29
113#define DOCG4_SEQ_PAGEWRITE 0x16
114#define DOCG4_SEQ_PAGEPROG 0x1e
115#define DOCG4_SEQ_BLOCKERASE 0x24
116
117/* DOC_FLASHCOMMAND register commands */
118#define DOCG4_CMD_PAGE_READ 0x00
119#define DOC_CMD_ERASECYCLE2 0xd0
120#define DOCG4_CMD_FLUSH 0x70
121#define DOCG4_CMD_READ2 0x30
122#define DOC_CMD_PROG_BLOCK_ADDR 0x60
123#define DOCG4_CMD_PAGEWRITE 0x80
124#define DOC_CMD_PROG_CYCLE2 0x10
125#define DOC_CMD_RESET 0xff
126
127/* DOC_POWERMODE register bits */
128#define DOC_POWERDOWN_READY 0x80
129
130/* DOC_FLASHCONTROL register bits */
131#define DOC_CTRL_CE 0x10
132#define DOC_CTRL_UNKNOWN 0x40
133#define DOC_CTRL_FLASHREADY 0x01
134
135/* DOC_ECCCONF0 register bits */
136#define DOC_ECCCONF0_READ_MODE 0x8000
137#define DOC_ECCCONF0_UNKNOWN 0x2000
138#define DOC_ECCCONF0_ECC_ENABLE 0x1000
139#define DOC_ECCCONF0_DATA_BYTES_MASK 0x07ff
140
141/* DOC_ECCCONF1 register bits */
142#define DOC_ECCCONF1_BCH_SYNDROM_ERR 0x80
143#define DOC_ECCCONF1_ECC_ENABLE 0x07
144#define DOC_ECCCONF1_PAGE_IS_WRITTEN 0x20
145
146/* DOC_ASICMODE register bits */
147#define DOC_ASICMODE_RESET 0x00
148#define DOC_ASICMODE_NORMAL 0x01
149#define DOC_ASICMODE_POWERDOWN 0x02
150#define DOC_ASICMODE_MDWREN 0x04
151#define DOC_ASICMODE_BDETCT_RESET 0x08
152#define DOC_ASICMODE_RSTIN_RESET 0x10
153#define DOC_ASICMODE_RAM_WE 0x20
154
155/* good status values read after read/write/erase operations */
156#define DOCG4_PROGSTATUS_GOOD 0x51
157#define DOCG4_PROGSTATUS_GOOD_2 0xe0
158
159/*
160 * On read operations (page and oob-only), the first byte read from I/O reg is a
161 * status. On error, it reads 0x73; otherwise, it reads either 0x71 (first read
162 * after reset only) or 0x51, so bit 1 is presumed to be an error indicator.
163 */
164#define DOCG4_READ_ERROR 0x02 /* bit 1 indicates read error */
165
166/* anatomy of the device */
167#define DOCG4_CHIP_SIZE 0x8000000
168#define DOCG4_PAGE_SIZE 0x200
169#define DOCG4_PAGES_PER_BLOCK 0x200
170#define DOCG4_BLOCK_SIZE (DOCG4_PAGES_PER_BLOCK * DOCG4_PAGE_SIZE)
171#define DOCG4_NUMBLOCKS (DOCG4_CHIP_SIZE / DOCG4_BLOCK_SIZE)
172#define DOCG4_OOB_SIZE 0x10
173#define DOCG4_CHIP_SHIFT 27 /* log_2(DOCG4_CHIP_SIZE) */
174#define DOCG4_PAGE_SHIFT 9 /* log_2(DOCG4_PAGE_SIZE) */
175#define DOCG4_ERASE_SHIFT 18 /* log_2(DOCG4_BLOCK_SIZE) */
176
177/* all but the last byte is included in ecc calculation */
178#define DOCG4_BCH_SIZE (DOCG4_PAGE_SIZE + DOCG4_OOB_SIZE - 1)
179
180#define DOCG4_USERDATA_LEN 520 /* 512 byte page plus 8 oob avail to user */
181
182/* expected values from the ID registers */
183#define DOCG4_IDREG1_VALUE 0x0400
184#define DOCG4_IDREG2_VALUE 0xfbff
185
186/* primitive polynomial used to build the Galois field used by hw ecc gen */
187#define DOCG4_PRIMITIVE_POLY 0x4443
188
189#define DOCG4_M 14 /* Galois field is of order 2^14 */
190#define DOCG4_T 4 /* BCH alg corrects up to 4 bit errors */
191
192#define DOCG4_FACTORY_BBT_PAGE 16 /* page where read-only factory bbt lives */
193
194/*
195 * Oob bytes 0 - 6 are available to the user.
196 * Byte 7 is hamming ecc for first 7 bytes. Bytes 8 - 14 are hw-generated ecc.
197 * Byte 15 (the last) is used by the driver as a "page written" flag.
198 */
199static struct nand_ecclayout docg4_oobinfo = {
200 .eccbytes = 9,
201 .eccpos = {7, 8, 9, 10, 11, 12, 13, 14, 15},
202 .oobavail = 7,
203 .oobfree = { {0, 7} }
204};
205
206/*
207 * The device has a nop register which M-Sys claims is for the purpose of
208 * inserting precise delays. But beware; at least some operations fail if the
209 * nop writes are replaced with a generic delay!
210 */
211static inline void write_nop(void __iomem *docptr)
212{
213 writew(0, docptr + DOC_NOP);
214}
215
216static void docg4_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
217{
218 int i;
219 struct nand_chip *nand = mtd->priv;
220 uint16_t *p = (uint16_t *) buf;
221 len >>= 1;
222
223 for (i = 0; i < len; i++)
224 p[i] = readw(nand->IO_ADDR_R);
225}
226
227static void docg4_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
228{
229 int i;
230 struct nand_chip *nand = mtd->priv;
231 uint16_t *p = (uint16_t *) buf;
232 len >>= 1;
233
234 for (i = 0; i < len; i++)
235 writew(p[i], nand->IO_ADDR_W);
236}
237
238static int poll_status(struct docg4_priv *doc)
239{
240 /*
241 * Busy-wait for the FLASHREADY bit to be set in the FLASHCONTROL
242 * register. Operations known to take a long time (e.g., block erase)
243 * should sleep for a while before calling this.
244 */
245
246 uint16_t flash_status;
247 unsigned int timeo;
248 void __iomem *docptr = doc->virtadr;
249
250 dev_dbg(doc->dev, "%s...\n", __func__);
251
252 /* hardware quirk requires reading twice initially */
253 flash_status = readw(docptr + DOC_FLASHCONTROL);
254
255 timeo = 1000;
256 do {
257 cpu_relax();
258 flash_status = readb(docptr + DOC_FLASHCONTROL);
259 } while (!(flash_status & DOC_CTRL_FLASHREADY) && --timeo);
260
261
262 if (!timeo) {
263 dev_err(doc->dev, "%s: timed out!\n", __func__);
264 return NAND_STATUS_FAIL;
265 }
266
267 if (unlikely(timeo < 50))
268 dev_warn(doc->dev, "%s: nearly timed out; %d remaining\n",
269 __func__, timeo);
270
271 return 0;
272}
273
274
275static int docg4_wait(struct mtd_info *mtd, struct nand_chip *nand)
276{
277
278 struct docg4_priv *doc = nand->priv;
279 int status = NAND_STATUS_WP; /* inverse logic?? */
280 dev_dbg(doc->dev, "%s...\n", __func__);
281
282 /* report any previously unreported error */
283 if (doc->status) {
284 status |= doc->status;
285 doc->status = 0;
286 return status;
287 }
288
289 status |= poll_status(doc);
290 return status;
291}
292
293static void docg4_select_chip(struct mtd_info *mtd, int chip)
294{
295 /*
296 * Select among multiple cascaded chips ("floors"). Multiple floors are
297 * not yet supported, so the only valid non-negative value is 0.
298 */
299 struct nand_chip *nand = mtd->priv;
300 struct docg4_priv *doc = nand->priv;
301 void __iomem *docptr = doc->virtadr;
302
303 dev_dbg(doc->dev, "%s: chip %d\n", __func__, chip);
304
305 if (chip < 0)
306 return; /* deselected */
307
308 if (chip > 0)
309 dev_warn(doc->dev, "multiple floors currently unsupported\n");
310
311 writew(0, docptr + DOC_DEVICESELECT);
312}
313
314static void reset(struct mtd_info *mtd)
315{
316 /* full device reset */
317
318 struct nand_chip *nand = mtd->priv;
319 struct docg4_priv *doc = nand->priv;
320 void __iomem *docptr = doc->virtadr;
321
322 writew(DOC_ASICMODE_RESET | DOC_ASICMODE_MDWREN,
323 docptr + DOC_ASICMODE);
324 writew(~(DOC_ASICMODE_RESET | DOC_ASICMODE_MDWREN),
325 docptr + DOC_ASICMODECONFIRM);
326 write_nop(docptr);
327
328 writew(DOC_ASICMODE_NORMAL | DOC_ASICMODE_MDWREN,
329 docptr + DOC_ASICMODE);
330 writew(~(DOC_ASICMODE_NORMAL | DOC_ASICMODE_MDWREN),
331 docptr + DOC_ASICMODECONFIRM);
332
333 writew(DOC_ECCCONF1_ECC_ENABLE, docptr + DOC_ECCCONF1);
334
335 poll_status(doc);
336}
337
338static void read_hw_ecc(void __iomem *docptr, uint8_t *ecc_buf)
339{
340 /* read the 7 hw-generated ecc bytes */
341
342 int i;
343 for (i = 0; i < 7; i++) { /* hw quirk; read twice */
344 ecc_buf[i] = readb(docptr + DOC_BCH_SYNDROM(i));
345 ecc_buf[i] = readb(docptr + DOC_BCH_SYNDROM(i));
346 }
347}
348
349static int correct_data(struct mtd_info *mtd, uint8_t *buf, int page)
350{
351 /*
352 * Called after a page read when hardware reports bitflips.
353 * Up to four bitflips can be corrected.
354 */
355
356 struct nand_chip *nand = mtd->priv;
357 struct docg4_priv *doc = nand->priv;
358 void __iomem *docptr = doc->virtadr;
359 int i, numerrs, errpos[4];
360 const uint8_t blank_read_hwecc[8] = {
361 0xcf, 0x72, 0xfc, 0x1b, 0xa9, 0xc7, 0xb9, 0 };
362
363 read_hw_ecc(docptr, doc->ecc_buf); /* read 7 hw-generated ecc bytes */
364
365 /* check if read error is due to a blank page */
366 if (!memcmp(doc->ecc_buf, blank_read_hwecc, 7))
367 return 0; /* yes */
368
369 /* skip additional check of "written flag" if ignore_badblocks */
370 if (ignore_badblocks == false) {
371
372 /*
373 * If the hw ecc bytes are not those of a blank page, there's
374 * still a chance that the page is blank, but was read with
375 * errors. Check the "written flag" in last oob byte, which
376 * is set to zero when a page is written. If more than half
377 * the bits are set, assume a blank page. Unfortunately, the
378 * bit flips(s) are not reported in stats.
379 */
380
381 if (doc->oob_buf[15]) {
382 int bit, numsetbits = 0;
383 unsigned long written_flag = doc->oob_buf[15];
384 for_each_set_bit(bit, &written_flag, 8)
385 numsetbits++;
386 if (numsetbits > 4) { /* assume blank */
387 dev_warn(doc->dev,
388 "error(s) in blank page "
389 "at offset %08x\n",
390 page * DOCG4_PAGE_SIZE);
391 return 0;
392 }
393 }
394 }
395
396 /*
397 * The hardware ecc unit produces oob_ecc ^ calc_ecc. The kernel's bch
398 * algorithm is used to decode this. However the hw operates on page
399 * data in a bit order that is the reverse of that of the bch alg,
400 * requiring that the bits be reversed on the result. Thanks to Ivan
401 * Djelic for his analysis!
402 */
403 for (i = 0; i < 7; i++)
404 doc->ecc_buf[i] = bitrev8(doc->ecc_buf[i]);
405
406 numerrs = decode_bch(doc->bch, NULL, DOCG4_USERDATA_LEN, NULL,
407 doc->ecc_buf, NULL, errpos);
408
409 if (numerrs == -EBADMSG) {
410 dev_warn(doc->dev, "uncorrectable errors at offset %08x\n",
411 page * DOCG4_PAGE_SIZE);
412 return -EBADMSG;
413 }
414
415 BUG_ON(numerrs < 0); /* -EINVAL, or anything other than -EBADMSG */
416
417 /* undo last step in BCH alg (modulo mirroring not needed) */
418 for (i = 0; i < numerrs; i++)
419 errpos[i] = (errpos[i] & ~7)|(7-(errpos[i] & 7));
420
421 /* fix the errors */
422 for (i = 0; i < numerrs; i++) {
423
424 /* ignore if error within oob ecc bytes */
425 if (errpos[i] > DOCG4_USERDATA_LEN * 8)
426 continue;
427
428 /* if error within oob area preceeding ecc bytes... */
429 if (errpos[i] > DOCG4_PAGE_SIZE * 8)
430 change_bit(errpos[i] - DOCG4_PAGE_SIZE * 8,
431 (unsigned long *)doc->oob_buf);
432
433 else /* error in page data */
434 change_bit(errpos[i], (unsigned long *)buf);
435 }
436
437 dev_notice(doc->dev, "%d error(s) corrected at offset %08x\n",
438 numerrs, page * DOCG4_PAGE_SIZE);
439
440 return numerrs;
441}
442
443static uint8_t docg4_read_byte(struct mtd_info *mtd)
444{
445 struct nand_chip *nand = mtd->priv;
446 struct docg4_priv *doc = nand->priv;
447
448 dev_dbg(doc->dev, "%s\n", __func__);
449
450 if (doc->last_command.command == NAND_CMD_STATUS) {
451 int status;
452
453 /*
454 * Previous nand command was status request, so nand
455 * infrastructure code expects to read the status here. If an
456 * error occurred in a previous operation, report it.
457 */
458 doc->last_command.command = 0;
459
460 if (doc->status) {
461 status = doc->status;
462 doc->status = 0;
463 }
464
465 /* why is NAND_STATUS_WP inverse logic?? */
466 else
467 status = NAND_STATUS_WP | NAND_STATUS_READY;
468
469 return status;
470 }
471
472 dev_warn(doc->dev, "unexpectd call to read_byte()\n");
473
474 return 0;
475}
476
477static void write_addr(struct docg4_priv *doc, uint32_t docg4_addr)
478{
479 /* write the four address bytes packed in docg4_addr to the device */
480
481 void __iomem *docptr = doc->virtadr;
482 writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
483 docg4_addr >>= 8;
484 writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
485 docg4_addr >>= 8;
486 writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
487 docg4_addr >>= 8;
488 writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
489}
490
491static int read_progstatus(struct docg4_priv *doc)
492{
493 /*
494 * This apparently checks the status of programming. Done after an
495 * erasure, and after page data is written. On error, the status is
496 * saved, to be later retrieved by the nand infrastructure code.
497 */
498 void __iomem *docptr = doc->virtadr;
499
500 /* status is read from the I/O reg */
501 uint16_t status1 = readw(docptr + DOC_IOSPACE_DATA);
502 uint16_t status2 = readw(docptr + DOC_IOSPACE_DATA);
503 uint16_t status3 = readw(docptr + DOCG4_MYSTERY_REG);
504
505 dev_dbg(doc->dev, "docg4: %s: %02x %02x %02x\n",
506 __func__, status1, status2, status3);
507
508 if (status1 != DOCG4_PROGSTATUS_GOOD
509 || status2 != DOCG4_PROGSTATUS_GOOD_2
510 || status3 != DOCG4_PROGSTATUS_GOOD_2) {
511 doc->status = NAND_STATUS_FAIL;
512 dev_warn(doc->dev, "read_progstatus failed: "
513 "%02x, %02x, %02x\n", status1, status2, status3);
514 return -EIO;
515 }
516 return 0;
517}
518
519static int pageprog(struct mtd_info *mtd)
520{
521 /*
522 * Final step in writing a page. Writes the contents of its
523 * internal buffer out to the flash array, or some such.
524 */
525
526 struct nand_chip *nand = mtd->priv;
527 struct docg4_priv *doc = nand->priv;
528 void __iomem *docptr = doc->virtadr;
529 int retval = 0;
530
531 dev_dbg(doc->dev, "docg4: %s\n", __func__);
532
533 writew(DOCG4_SEQ_PAGEPROG, docptr + DOC_FLASHSEQUENCE);
534 writew(DOC_CMD_PROG_CYCLE2, docptr + DOC_FLASHCOMMAND);
535 write_nop(docptr);
536 write_nop(docptr);
537
538 /* Just busy-wait; usleep_range() slows things down noticeably. */
539 poll_status(doc);
540
541 writew(DOCG4_SEQ_FLUSH, docptr + DOC_FLASHSEQUENCE);
542 writew(DOCG4_CMD_FLUSH, docptr + DOC_FLASHCOMMAND);
543 writew(DOC_ECCCONF0_READ_MODE | 4, docptr + DOC_ECCCONF0);
544 write_nop(docptr);
545 write_nop(docptr);
546 write_nop(docptr);
547 write_nop(docptr);
548 write_nop(docptr);
549
550 retval = read_progstatus(doc);
551 writew(0, docptr + DOC_DATAEND);
552 write_nop(docptr);
553 poll_status(doc);
554 write_nop(docptr);
555
556 return retval;
557}
558
559static void sequence_reset(struct mtd_info *mtd)
560{
561 /* common starting sequence for all operations */
562
563 struct nand_chip *nand = mtd->priv;
564 struct docg4_priv *doc = nand->priv;
565 void __iomem *docptr = doc->virtadr;
566
567 writew(DOC_CTRL_UNKNOWN | DOC_CTRL_CE, docptr + DOC_FLASHCONTROL);
568 writew(DOC_SEQ_RESET, docptr + DOC_FLASHSEQUENCE);
569 writew(DOC_CMD_RESET, docptr + DOC_FLASHCOMMAND);
570 write_nop(docptr);
571 write_nop(docptr);
572 poll_status(doc);
573 write_nop(docptr);
574}
575
576static void read_page_prologue(struct mtd_info *mtd, uint32_t docg4_addr)
577{
578 /* first step in reading a page */
579
580 struct nand_chip *nand = mtd->priv;
581 struct docg4_priv *doc = nand->priv;
582 void __iomem *docptr = doc->virtadr;
583
584 dev_dbg(doc->dev,
585 "docg4: %s: g4 page %08x\n", __func__, docg4_addr);
586
587 sequence_reset(mtd);
588
589 writew(DOCG4_SEQ_PAGE_READ, docptr + DOC_FLASHSEQUENCE);
590 writew(DOCG4_CMD_PAGE_READ, docptr + DOC_FLASHCOMMAND);
591 write_nop(docptr);
592
593 write_addr(doc, docg4_addr);
594
595 write_nop(docptr);
596 writew(DOCG4_CMD_READ2, docptr + DOC_FLASHCOMMAND);
597 write_nop(docptr);
598 write_nop(docptr);
599
600 poll_status(doc);
601}
602
603static void write_page_prologue(struct mtd_info *mtd, uint32_t docg4_addr)
604{
605 /* first step in writing a page */
606
607 struct nand_chip *nand = mtd->priv;
608 struct docg4_priv *doc = nand->priv;
609 void __iomem *docptr = doc->virtadr;
610
611 dev_dbg(doc->dev,
612 "docg4: %s: g4 addr: %x\n", __func__, docg4_addr);
613 sequence_reset(mtd);
614 writew(DOCG4_SEQ_PAGEWRITE, docptr + DOC_FLASHSEQUENCE);
615 writew(DOCG4_CMD_PAGEWRITE, docptr + DOC_FLASHCOMMAND);
616 write_nop(docptr);
617 write_addr(doc, docg4_addr);
618 write_nop(docptr);
619 write_nop(docptr);
620 poll_status(doc);
621}
622
623static uint32_t mtd_to_docg4_address(int page, int column)
624{
625 /*
626 * Convert mtd address to format used by the device, 32 bit packed.
627 *
628 * Some notes on G4 addressing... The M-Sys documentation on this device
629 * claims that pages are 2K in length, and indeed, the format of the
630 * address used by the device reflects that. But within each page are
631 * four 512 byte "sub-pages", each with its own oob data that is
632 * read/written immediately after the 512 bytes of page data. This oob
633 * data contains the ecc bytes for the preceeding 512 bytes.
634 *
635 * Rather than tell the mtd nand infrastructure that page size is 2k,
636 * with four sub-pages each, we engage in a little subterfuge and tell
637 * the infrastructure code that pages are 512 bytes in size. This is
638 * done because during the course of reverse-engineering the device, I
639 * never observed an instance where an entire 2K "page" was read or
640 * written as a unit. Each "sub-page" is always addressed individually,
641 * its data read/written, and ecc handled before the next "sub-page" is
642 * addressed.
643 *
644 * This requires us to convert addresses passed by the mtd nand
645 * infrastructure code to those used by the device.
646 *
647 * The address that is written to the device consists of four bytes: the
648 * first two are the 2k page number, and the second is the index into
649 * the page. The index is in terms of 16-bit half-words and includes
650 * the preceeding oob data, so e.g., the index into the second
651 * "sub-page" is 0x108, and the full device address of the start of mtd
652 * page 0x201 is 0x00800108.
653 */
654 int g4_page = page / 4; /* device's 2K page */
655 int g4_index = (page % 4) * 0x108 + column/2; /* offset into page */
656 return (g4_page << 16) | g4_index; /* pack */
657}
658
659static void docg4_command(struct mtd_info *mtd, unsigned command, int column,
660 int page_addr)
661{
662 /* handle standard nand commands */
663
664 struct nand_chip *nand = mtd->priv;
665 struct docg4_priv *doc = nand->priv;
666 uint32_t g4_addr = mtd_to_docg4_address(page_addr, column);
667
668 dev_dbg(doc->dev, "%s %x, page_addr=%x, column=%x\n",
669 __func__, command, page_addr, column);
670
671 /*
672 * Save the command and its arguments. This enables emulation of
673 * standard flash devices, and also some optimizations.
674 */
675 doc->last_command.command = command;
676 doc->last_command.column = column;
677 doc->last_command.page = page_addr;
678
679 switch (command) {
680
681 case NAND_CMD_RESET:
682 reset(mtd);
683 break;
684
685 case NAND_CMD_READ0:
686 read_page_prologue(mtd, g4_addr);
687 break;
688
689 case NAND_CMD_STATUS:
690 /* next call to read_byte() will expect a status */
691 break;
692
693 case NAND_CMD_SEQIN:
694 write_page_prologue(mtd, g4_addr);
695
696 /* hack for deferred write of oob bytes */
697 if (doc->oob_page == page_addr)
698 memcpy(nand->oob_poi, doc->oob_buf, 16);
699 break;
700
701 case NAND_CMD_PAGEPROG:
702 pageprog(mtd);
703 break;
704
705 /* we don't expect these, based on review of nand_base.c */
706 case NAND_CMD_READOOB:
707 case NAND_CMD_READID:
708 case NAND_CMD_ERASE1:
709 case NAND_CMD_ERASE2:
710 dev_warn(doc->dev, "docg4_command: "
711 "unexpected nand command 0x%x\n", command);
712 break;
713
714 }
715}
716
717static int read_page(struct mtd_info *mtd, struct nand_chip *nand,
718 uint8_t *buf, int page, bool use_ecc)
719{
720 struct docg4_priv *doc = nand->priv;
721 void __iomem *docptr = doc->virtadr;
722 uint16_t status, edc_err, *buf16;
723
724 dev_dbg(doc->dev, "%s: page %08x\n", __func__, page);
725
726 writew(DOC_ECCCONF0_READ_MODE |
727 DOC_ECCCONF0_ECC_ENABLE |
728 DOC_ECCCONF0_UNKNOWN |
729 DOCG4_BCH_SIZE,
730 docptr + DOC_ECCCONF0);
731 write_nop(docptr);
732 write_nop(docptr);
733 write_nop(docptr);
734 write_nop(docptr);
735 write_nop(docptr);
736
737 /* the 1st byte from the I/O reg is a status; the rest is page data */
738 status = readw(docptr + DOC_IOSPACE_DATA);
739 if (status & DOCG4_READ_ERROR) {
740 dev_err(doc->dev,
741 "docg4_read_page: bad status: 0x%02x\n", status);
742 writew(0, docptr + DOC_DATAEND);
743 return -EIO;
744 }
745
746 dev_dbg(doc->dev, "%s: status = 0x%x\n", __func__, status);
747
748 docg4_read_buf(mtd, buf, DOCG4_PAGE_SIZE); /* read the page data */
749
750 /*
751 * Diskonchips read oob immediately after a page read. Mtd
752 * infrastructure issues a separate command for reading oob after the
753 * page is read. So we save the oob bytes in a local buffer and just
754 * copy it if the next command reads oob from the same page.
755 */
756
757 /* first 14 oob bytes read from I/O reg */
758 docg4_read_buf(mtd, doc->oob_buf, 14);
759
760 /* last 2 read from another reg */
761 buf16 = (uint16_t *)(doc->oob_buf + 14);
762 *buf16 = readw(docptr + DOCG4_MYSTERY_REG);
763
764 write_nop(docptr);
765
766 if (likely(use_ecc == true)) {
767
768 /* read the register that tells us if bitflip(s) detected */
769 edc_err = readw(docptr + DOC_ECCCONF1);
770 edc_err = readw(docptr + DOC_ECCCONF1);
771 dev_dbg(doc->dev, "%s: edc_err = 0x%02x\n", __func__, edc_err);
772
773 /* If bitflips are reported, attempt to correct with ecc */
774 if (edc_err & DOC_ECCCONF1_BCH_SYNDROM_ERR) {
775 int bits_corrected = correct_data(mtd, buf, page);
776 if (bits_corrected == -EBADMSG)
777 mtd->ecc_stats.failed++;
778 else
779 mtd->ecc_stats.corrected += bits_corrected;
780 }
781 }
782
783 writew(0, docptr + DOC_DATAEND);
784 return 0;
785}
786
787
788static int docg4_read_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
789 uint8_t *buf, int page)
790{
791 return read_page(mtd, nand, buf, page, false);
792}
793
794static int docg4_read_page(struct mtd_info *mtd, struct nand_chip *nand,
795 uint8_t *buf, int page)
796{
797 return read_page(mtd, nand, buf, page, true);
798}
799
800static int docg4_read_oob(struct mtd_info *mtd, struct nand_chip *nand,
801 int page, int sndcmd)
802{
803 struct docg4_priv *doc = nand->priv;
804 void __iomem *docptr = doc->virtadr;
805 uint16_t status;
806
807 dev_dbg(doc->dev, "%s: page %x\n", __func__, page);
808
809 /*
810 * Oob bytes are read as part of a normal page read. If the previous
811 * nand command was a read of the page whose oob is now being read, just
812 * copy the oob bytes that we saved in a local buffer and avoid a
813 * separate oob read.
814 */
815 if (doc->last_command.command == NAND_CMD_READ0 &&
816 doc->last_command.page == page) {
817 memcpy(nand->oob_poi, doc->oob_buf, 16);
818 return 0;
819 }
820
821 /*
822 * Separate read of oob data only.
823 */
824 docg4_command(mtd, NAND_CMD_READ0, nand->ecc.size, page);
825
826 writew(DOC_ECCCONF0_READ_MODE | DOCG4_OOB_SIZE, docptr + DOC_ECCCONF0);
827 write_nop(docptr);
828 write_nop(docptr);
829 write_nop(docptr);
830 write_nop(docptr);
831 write_nop(docptr);
832
833 /* the 1st byte from the I/O reg is a status; the rest is oob data */
834 status = readw(docptr + DOC_IOSPACE_DATA);
835 if (status & DOCG4_READ_ERROR) {
836 dev_warn(doc->dev,
837 "docg4_read_oob failed: status = 0x%02x\n", status);
838 return -EIO;
839 }
840
841 dev_dbg(doc->dev, "%s: status = 0x%x\n", __func__, status);
842
843 docg4_read_buf(mtd, nand->oob_poi, 16);
844
845 write_nop(docptr);
846 write_nop(docptr);
847 write_nop(docptr);
848 writew(0, docptr + DOC_DATAEND);
849 write_nop(docptr);
850
851 return 0;
852}
853
854static void docg4_erase_block(struct mtd_info *mtd, int page)
855{
856 struct nand_chip *nand = mtd->priv;
857 struct docg4_priv *doc = nand->priv;
858 void __iomem *docptr = doc->virtadr;
859 uint16_t g4_page;
860
861 dev_dbg(doc->dev, "%s: page %04x\n", __func__, page);
862
863 sequence_reset(mtd);
864
865 writew(DOCG4_SEQ_BLOCKERASE, docptr + DOC_FLASHSEQUENCE);
866 writew(DOC_CMD_PROG_BLOCK_ADDR, docptr + DOC_FLASHCOMMAND);
867 write_nop(docptr);
868
869 /* only 2 bytes of address are written to specify erase block */
870 g4_page = (uint16_t)(page / 4); /* to g4's 2k page addressing */
871 writeb(g4_page & 0xff, docptr + DOC_FLASHADDRESS);
872 g4_page >>= 8;
873 writeb(g4_page & 0xff, docptr + DOC_FLASHADDRESS);
874 write_nop(docptr);
875
876 /* start the erasure */
877 writew(DOC_CMD_ERASECYCLE2, docptr + DOC_FLASHCOMMAND);
878 write_nop(docptr);
879 write_nop(docptr);
880
881 usleep_range(500, 1000); /* erasure is long; take a snooze */
882 poll_status(doc);
883 writew(DOCG4_SEQ_FLUSH, docptr + DOC_FLASHSEQUENCE);
884 writew(DOCG4_CMD_FLUSH, docptr + DOC_FLASHCOMMAND);
885 writew(DOC_ECCCONF0_READ_MODE | 4, docptr + DOC_ECCCONF0);
886 write_nop(docptr);
887 write_nop(docptr);
888 write_nop(docptr);
889 write_nop(docptr);
890 write_nop(docptr);
891
892 read_progstatus(doc);
893
894 writew(0, docptr + DOC_DATAEND);
895 write_nop(docptr);
896 poll_status(doc);
897 write_nop(docptr);
898}
899
900static void write_page(struct mtd_info *mtd, struct nand_chip *nand,
901 const uint8_t *buf, bool use_ecc)
902{
903 struct docg4_priv *doc = nand->priv;
904 void __iomem *docptr = doc->virtadr;
905 uint8_t ecc_buf[8];
906
907 dev_dbg(doc->dev, "%s...\n", __func__);
908
909 writew(DOC_ECCCONF0_ECC_ENABLE |
910 DOC_ECCCONF0_UNKNOWN |
911 DOCG4_BCH_SIZE,
912 docptr + DOC_ECCCONF0);
913 write_nop(docptr);
914
915 /* write the page data */
916 docg4_write_buf16(mtd, buf, DOCG4_PAGE_SIZE);
917
918 /* oob bytes 0 through 5 are written to I/O reg */
919 docg4_write_buf16(mtd, nand->oob_poi, 6);
920
921 /* oob byte 6 written to a separate reg */
922 writew(nand->oob_poi[6], docptr + DOCG4_OOB_6_7);
923
924 write_nop(docptr);
925 write_nop(docptr);
926
927 /* write hw-generated ecc bytes to oob */
928 if (likely(use_ecc == true)) {
929 /* oob byte 7 is hamming code */
930 uint8_t hamming = readb(docptr + DOC_HAMMINGPARITY);
931 hamming = readb(docptr + DOC_HAMMINGPARITY); /* 2nd read */
932 writew(hamming, docptr + DOCG4_OOB_6_7);
933 write_nop(docptr);
934
935 /* read the 7 bch bytes from ecc regs */
936 read_hw_ecc(docptr, ecc_buf);
937 ecc_buf[7] = 0; /* clear the "page written" flag */
938 }
939
940 /* write user-supplied bytes to oob */
941 else {
942 writew(nand->oob_poi[7], docptr + DOCG4_OOB_6_7);
943 write_nop(docptr);
944 memcpy(ecc_buf, &nand->oob_poi[8], 8);
945 }
946
947 docg4_write_buf16(mtd, ecc_buf, 8);
948 write_nop(docptr);
949 write_nop(docptr);
950 writew(0, docptr + DOC_DATAEND);
951 write_nop(docptr);
952}
953
954static void docg4_write_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
955 const uint8_t *buf)
956{
957 return write_page(mtd, nand, buf, false);
958}
959
960static void docg4_write_page(struct mtd_info *mtd, struct nand_chip *nand,
961 const uint8_t *buf)
962{
963 return write_page(mtd, nand, buf, true);
964}
965
966static int docg4_write_oob(struct mtd_info *mtd, struct nand_chip *nand,
967 int page)
968{
969 /*
970 * Writing oob-only is not really supported, because MLC nand must write
971 * oob bytes at the same time as page data. Nonetheless, we save the
972 * oob buffer contents here, and then write it along with the page data
973 * if the same page is subsequently written. This allows user space
974 * utilities that write the oob data prior to the page data to work
975 * (e.g., nandwrite). The disdvantage is that, if the intention was to
976 * write oob only, the operation is quietly ignored. Also, oob can get
977 * corrupted if two concurrent processes are running nandwrite.
978 */
979
980 /* note that bytes 7..14 are hw generated hamming/ecc and overwritten */
981 struct docg4_priv *doc = nand->priv;
982 doc->oob_page = page;
983 memcpy(doc->oob_buf, nand->oob_poi, 16);
984 return 0;
985}
986
987static int __init read_factory_bbt(struct mtd_info *mtd)
988{
989 /*
990 * The device contains a read-only factory bad block table. Read it and
991 * update the memory-based bbt accordingly.
992 */
993
994 struct nand_chip *nand = mtd->priv;
995 struct docg4_priv *doc = nand->priv;
996 uint32_t g4_addr = mtd_to_docg4_address(DOCG4_FACTORY_BBT_PAGE, 0);
997 uint8_t *buf;
998 int i, block, status;
999
1000 buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL);
1001 if (buf == NULL)
1002 return -ENOMEM;
1003
1004 read_page_prologue(mtd, g4_addr);
1005 status = docg4_read_page(mtd, nand, buf, DOCG4_FACTORY_BBT_PAGE);
1006 if (status)
1007 goto exit;
1008
1009 /*
1010 * If no memory-based bbt was created, exit. This will happen if module
1011 * parameter ignore_badblocks is set. Then why even call this function?
1012 * For an unknown reason, block erase always fails if it's the first
1013 * operation after device power-up. The above read ensures it never is.
1014 * Ugly, I know.
1015 */
1016 if (nand->bbt == NULL) /* no memory-based bbt */
1017 goto exit;
1018
1019 /*
1020 * Parse factory bbt and update memory-based bbt. Factory bbt format is
1021 * simple: one bit per block, block numbers increase left to right (msb
1022 * to lsb). Bit clear means bad block.
1023 */
1024 for (i = block = 0; block < DOCG4_NUMBLOCKS; block += 8, i++) {
1025 int bitnum;
1026 unsigned long bits = ~buf[i];
1027 for_each_set_bit(bitnum, &bits, 8) {
1028 int badblock = block + 7 - bitnum;
1029 nand->bbt[badblock / 4] |=
1030 0x03 << ((badblock % 4) * 2);
1031 mtd->ecc_stats.badblocks++;
1032 dev_notice(doc->dev, "factory-marked bad block: %d\n",
1033 badblock);
1034 }
1035 }
1036 exit:
1037 kfree(buf);
1038 return status;
1039}
1040
1041static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)
1042{
1043 /*
1044 * Mark a block as bad. Bad blocks are marked in the oob area of the
1045 * first page of the block. The default scan_bbt() in the nand
1046 * infrastructure code works fine for building the memory-based bbt
1047 * during initialization, as does the nand infrastructure function that
1048 * checks if a block is bad by reading the bbt. This function replaces
1049 * the nand default because writes to oob-only are not supported.
1050 */
1051
1052 int ret, i;
1053 uint8_t *buf;
1054 struct nand_chip *nand = mtd->priv;
1055 struct docg4_priv *doc = nand->priv;
1056 struct nand_bbt_descr *bbtd = nand->badblock_pattern;
1057 int block = (int)(ofs >> nand->bbt_erase_shift);
1058 int page = (int)(ofs >> nand->page_shift);
1059 uint32_t g4_addr = mtd_to_docg4_address(page, 0);
1060
1061 dev_dbg(doc->dev, "%s: %08llx\n", __func__, ofs);
1062
1063 if (unlikely(ofs & (DOCG4_BLOCK_SIZE - 1)))
1064 dev_warn(doc->dev, "%s: ofs %llx not start of block!\n",
1065 __func__, ofs);
1066
1067 /* allocate blank buffer for page data */
1068 buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL);
1069 if (buf == NULL)
1070 return -ENOMEM;
1071
1072 /* update bbt in memory */
1073 nand->bbt[block / 4] |= 0x01 << ((block & 0x03) * 2);
1074
1075 /* write bit-wise negation of pattern to oob buffer */
1076 memset(nand->oob_poi, 0xff, mtd->oobsize);
1077 for (i = 0; i < bbtd->len; i++)
1078 nand->oob_poi[bbtd->offs + i] = ~bbtd->pattern[i];
1079
1080 /* write first page of block */
1081 write_page_prologue(mtd, g4_addr);
1082 docg4_write_page(mtd, nand, buf);
1083 ret = pageprog(mtd);
1084 if (!ret)
1085 mtd->ecc_stats.badblocks++;
1086
1087 kfree(buf);
1088
1089 return ret;
1090}
1091
1092static int docg4_block_neverbad(struct mtd_info *mtd, loff_t ofs, int getchip)
1093{
1094 /* only called when module_param ignore_badblocks is set */
1095 return 0;
1096}
1097
1098static int docg4_suspend(struct platform_device *pdev, pm_message_t state)
1099{
1100 /*
1101 * Put the device into "deep power-down" mode. Note that CE# must be
1102 * deasserted for this to take effect. The xscale, e.g., can be
1103 * configured to float this signal when the processor enters power-down,
1104 * and a suitable pull-up ensures its deassertion.
1105 */
1106
1107 int i;
1108 uint8_t pwr_down;
1109 struct docg4_priv *doc = platform_get_drvdata(pdev);
1110 void __iomem *docptr = doc->virtadr;
1111
1112 dev_dbg(doc->dev, "%s...\n", __func__);
1113
1114 /* poll the register that tells us we're ready to go to sleep */
1115 for (i = 0; i < 10; i++) {
1116 pwr_down = readb(docptr + DOC_POWERMODE);
1117 if (pwr_down & DOC_POWERDOWN_READY)
1118 break;
1119 usleep_range(1000, 4000);
1120 }
1121
1122 if (pwr_down & DOC_POWERDOWN_READY) {
1123 dev_err(doc->dev, "suspend failed; "
1124 "timeout polling DOC_POWERDOWN_READY\n");
1125 return -EIO;
1126 }
1127
1128 writew(DOC_ASICMODE_POWERDOWN | DOC_ASICMODE_MDWREN,
1129 docptr + DOC_ASICMODE);
1130 writew(~(DOC_ASICMODE_POWERDOWN | DOC_ASICMODE_MDWREN),
1131 docptr + DOC_ASICMODECONFIRM);
1132
1133 write_nop(docptr);
1134
1135 return 0;
1136}
1137
1138static int docg4_resume(struct platform_device *pdev)
1139{
1140
1141 /*
1142 * Exit power-down. Twelve consecutive reads of the address below
1143 * accomplishes this, assuming CE# has been asserted.
1144 */
1145
1146 struct docg4_priv *doc = platform_get_drvdata(pdev);
1147 void __iomem *docptr = doc->virtadr;
1148 int i;
1149
1150 dev_dbg(doc->dev, "%s...\n", __func__);
1151
1152 for (i = 0; i < 12; i++)
1153 readb(docptr + 0x1fff);
1154
1155 return 0;
1156}
1157
1158static void __init init_mtd_structs(struct mtd_info *mtd)
1159{
1160 /* initialize mtd and nand data structures */
1161
1162 /*
1163 * Note that some of the following initializations are not usually
1164 * required within a nand driver because they are performed by the nand
1165 * infrastructure code as part of nand_scan(). In this case they need
1166 * to be initialized here because we skip call to nand_scan_ident() (the
1167 * first half of nand_scan()). The call to nand_scan_ident() is skipped
1168 * because for this device the chip id is not read in the manner of a
1169 * standard nand device. Unfortunately, nand_scan_ident() does other
1170 * things as well, such as call nand_set_defaults().
1171 */
1172
1173 struct nand_chip *nand = mtd->priv;
1174 struct docg4_priv *doc = nand->priv;
1175
1176 mtd->size = DOCG4_CHIP_SIZE;
1177 mtd->name = "Msys_Diskonchip_G4";
1178 mtd->writesize = DOCG4_PAGE_SIZE;
1179 mtd->erasesize = DOCG4_BLOCK_SIZE;
1180 mtd->oobsize = DOCG4_OOB_SIZE;
1181 nand->chipsize = DOCG4_CHIP_SIZE;
1182 nand->chip_shift = DOCG4_CHIP_SHIFT;
1183 nand->bbt_erase_shift = nand->phys_erase_shift = DOCG4_ERASE_SHIFT;
1184 nand->chip_delay = 20;
1185 nand->page_shift = DOCG4_PAGE_SHIFT;
1186 nand->pagemask = 0x3ffff;
1187 nand->badblockpos = NAND_LARGE_BADBLOCK_POS;
1188 nand->badblockbits = 8;
1189 nand->ecc.layout = &docg4_oobinfo;
1190 nand->ecc.mode = NAND_ECC_HW_SYNDROME;
1191 nand->ecc.size = DOCG4_PAGE_SIZE;
1192 nand->ecc.prepad = 8;
1193 nand->ecc.bytes = 8;
6a918bad 1194 nand->ecc.strength = DOCG4_T;
570469f3
MD		 1195 nand->options =
1196 NAND_BUSWIDTH_16 | NAND_NO_SUBPAGE_WRITE | NAND_NO_AUTOINCR;
1197 nand->IO_ADDR_R = nand->IO_ADDR_W = doc->virtadr + DOC_IOSPACE_DATA;
1198 nand->controller = &nand->hwcontrol;
1199 spin_lock_init(&nand->controller->lock);
1200 init_waitqueue_head(&nand->controller->wq);
1201
1202 /* methods */
1203 nand->cmdfunc = docg4_command;
1204 nand->waitfunc = docg4_wait;
1205 nand->select_chip = docg4_select_chip;
1206 nand->read_byte = docg4_read_byte;
1207 nand->block_markbad = docg4_block_markbad;
1208 nand->read_buf = docg4_read_buf;
1209 nand->write_buf = docg4_write_buf16;
1210 nand->scan_bbt = nand_default_bbt;
1211 nand->erase_cmd = docg4_erase_block;
1212 nand->ecc.read_page = docg4_read_page;
1213 nand->ecc.write_page = docg4_write_page;
1214 nand->ecc.read_page_raw = docg4_read_page_raw;
1215 nand->ecc.write_page_raw = docg4_write_page_raw;
1216 nand->ecc.read_oob = docg4_read_oob;
1217 nand->ecc.write_oob = docg4_write_oob;
1218
1219 /*
1220 * The way the nand infrastructure code is written, a memory-based bbt
1221 * is not created if NAND_SKIP_BBTSCAN is set. With no memory bbt,
1222 * nand->block_bad() is used. So when ignoring bad blocks, we skip the
1223 * scan and define a dummy block_bad() which always returns 0.
1224 */
1225 if (ignore_badblocks) {
1226 nand->options |= NAND_SKIP_BBTSCAN;
1227 nand->block_bad = docg4_block_neverbad;
1228 }
1229
1230}
1231
1232static int __init read_id_reg(struct mtd_info *mtd)
1233{
1234 struct nand_chip *nand = mtd->priv;
1235 struct docg4_priv *doc = nand->priv;
1236 void __iomem *docptr = doc->virtadr;
1237 uint16_t id1, id2;
1238
1239 /* check for presence of g4 chip by reading id registers */
1240 id1 = readw(docptr + DOC_CHIPID);
1241 id1 = readw(docptr + DOCG4_MYSTERY_REG);
1242 id2 = readw(docptr + DOC_CHIPID_INV);
1243 id2 = readw(docptr + DOCG4_MYSTERY_REG);
1244
1245 if (id1 == DOCG4_IDREG1_VALUE && id2 == DOCG4_IDREG2_VALUE) {
1246 dev_info(doc->dev,
1247 "NAND device: 128MiB Diskonchip G4 detected\n");
1248 return 0;
1249 }
1250
1251 return -ENODEV;
1252}
1253
1254static char const *part_probes[] = { "cmdlinepart", "saftlpart", NULL };
1255
1256static int __init probe_docg4(struct platform_device *pdev)
1257{
1258 struct mtd_info *mtd;
1259 struct nand_chip *nand;
1260 void __iomem *virtadr;
1261 struct docg4_priv *doc;
1262 int len, retval;
1263 struct resource *r;
1264 struct device *dev = &pdev->dev;
1265
1266 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1267 if (r == NULL) {
1268 dev_err(dev, "no io memory resource defined!\n");
1269 return -ENODEV;
1270 }
1271
1272 virtadr = ioremap(r->start, resource_size(r));
1273 if (!virtadr) {
2c4ae276 1274 dev_err(dev, "Diskonchip ioremap failed: %pR\n", r);
570469f3
MD		 1275 return -EIO;
1276 }
1277
1278 len = sizeof(struct mtd_info) + sizeof(struct nand_chip) +
1279 sizeof(struct docg4_priv);
1280 mtd = kzalloc(len, GFP_KERNEL);
1281 if (mtd == NULL) {
1282 retval = -ENOMEM;
1283 goto fail;
1284 }
1285 nand = (struct nand_chip *) (mtd + 1);
1286 doc = (struct docg4_priv *) (nand + 1);
1287 mtd->priv = nand;
1288 nand->priv = doc;
1289 mtd->owner = THIS_MODULE;
1290 doc->virtadr = virtadr;
1291 doc->dev = dev;
1292
1293 init_mtd_structs(mtd);
1294
1295 /* initialize kernel bch algorithm */
1296 doc->bch = init_bch(DOCG4_M, DOCG4_T, DOCG4_PRIMITIVE_POLY);
1297 if (doc->bch == NULL) {
1298 retval = -EINVAL;
1299 goto fail;
1300 }
1301
1302 platform_set_drvdata(pdev, doc);
1303
1304 reset(mtd);
1305 retval = read_id_reg(mtd);
1306 if (retval == -ENODEV) {
1307 dev_warn(dev, "No diskonchip G4 device found.\n");
1308 goto fail;
1309 }
1310
1311 retval = nand_scan_tail(mtd);
1312 if (retval)
1313 goto fail;
1314
1315 retval = read_factory_bbt(mtd);
1316 if (retval)
1317 goto fail;
1318
1319 retval = mtd_device_parse_register(mtd, part_probes, NULL, NULL, 0);
1320 if (retval)
1321 goto fail;
1322
1323 doc->mtd = mtd;
1324 return 0;
1325
1326 fail:
1327 iounmap(virtadr);
1328 if (mtd) {
1329 /* re-declarations avoid compiler warning */
1330 struct nand_chip *nand = mtd->priv;
1331 struct docg4_priv *doc = nand->priv;
1332 nand_release(mtd); /* deletes partitions and mtd devices */
1333 platform_set_drvdata(pdev, NULL);
1334 free_bch(doc->bch);
1335 kfree(mtd);
1336 }
1337
1338 return retval;
1339}
1340
1341static int __exit cleanup_docg4(struct platform_device *pdev)
1342{
1343 struct docg4_priv *doc = platform_get_drvdata(pdev);
1344 nand_release(doc->mtd);
1345 platform_set_drvdata(pdev, NULL);
1346 free_bch(doc->bch);
1347 kfree(doc->mtd);
1348 iounmap(doc->virtadr);
1349 return 0;
1350}
1351
1352static struct platform_driver docg4_driver = {
1353 .driver = {
1354 .name = "docg4",
1355 .owner = THIS_MODULE,
1356 },
1357 .suspend = docg4_suspend,
1358 .resume = docg4_resume,
1359 .remove = __exit_p(cleanup_docg4),
1360};
1361
1362static int __init docg4_init(void)
1363{
1364 return platform_driver_probe(&docg4_driver, probe_docg4);
1365}
1366
1367static void __exit docg4_exit(void)
1368{
1369 platform_driver_unregister(&docg4_driver);
1370}
1371
1372module_init(docg4_init);
1373module_exit(docg4_exit);
1374
1375MODULE_LICENSE("GPL");
1376MODULE_AUTHOR("Mike Dunn");
1377MODULE_DESCRIPTION("M-Systems DiskOnChip G4 device driver");
Linux 6.x block layer and io_uring tree(s)